#include<stdio.h>   
  #include<graphics.h>   
  #include<math.h>   
  #define   PI   3.1415926   
    
  main()   
  {   
  int   x,y,y1,r,r1;   
  double   a;   
  int   gdriver=DETECT,gmode;   
  initgraph(&gdriver,&gmode,"c:\\tc");   
  printf("Input   Radius(<80)\n");   
  scanf("%d",&r);   
  cleardevice();   
  setbkcolor(9);   
  setcolor(4);   
  y1=240-r;   
  for(a=0;a<2*PI;a+=PI/18)   
  {   
  x=r*cos(a)+320;   
  y=r*sin(a)+240;   
  r1=sqrt((x-320)*(x-320)+(y-y1)*(y-y1));   
  circle(x,y,r1);   
  }   
  getch();   
  closegraph();   
  }   

